redis-py
The Python interface to the Redis key-value store.
Installation | Usage | Advanced Topics | Contributing
Note: redis-py 5.0 is the last version of redis-py that supports Python 3.7, as it has reached end of life. redis-py 5.1 supports Python 3.8+.
Note: redis-py 6.1.0 is the last version of redis-py that supports Python 3.8, as it has reached end of life. redis-py 6.2.0 supports Python 3.9+.
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Installation
Start a redis via docker (for Redis versions >= 8.0):
docker run -p 6379:6379 -it redis:latest
Start a redis via docker (for Redis versions < 8.0):
docker run -p 6379:6379 -it redis/redis-stack:latest
To install redis-py, simply:
$ pip install redis
For faster performance, install redis with hiredis support, this provides a compiled response parser, and for most cases requires zero code changes.
By default, if hiredis >= 1.0 is available, redis-py will attempt to use it for response parsing.
$ pip install "redis[hiredis]"
Looking for a high-level library to handle object mapping? See redis-om-python!
Supported Redis Versions
The most recent version of this library supports Redis version 7.2, 7.4, 8.0, 8.2, 8.4, 8.6 and 8.8.
The table below highlights version compatibility of the most-recent library versions and redis versions.
| Library version |
Supported redis versions |
| 3.5.3 |
<= 6.2 Family of releases |
| >= 4.5.0 |
Version 5.0 to 7.0 |
| >= 5.0.0 |
Version 5.0 to 7.4 |
| >= 6.0.0 |
Version 7.2 to current |
Usage
Basic Example
>>> import redis
>>> r = redis.Redis(host='localhost', port=6379, db=0)
>>> r.set('foo', 'bar')
True
>>> r.get('foo')
b'bar'
The above code connects to localhost on port 6379, sets a value in Redis, and retrieves it. All responses are returned as bytes in Python, to receive decoded strings, set decode_responses=True. For this, and more connection options, see these examples.
RESP3 Support
redis-py supports RESP3 starting with version 5.0. Starting with redis-py 8.0,
clients use RESP3 on the wire by default while preserving legacy
RESP2-compatible Python response shapes for existing applications.
Set protocol=3 explicitly when your application should receive
RESP3-specific response shapes or when you want the wire protocol choice to be
visible in code. To force RESP2 on the wire, set protocol=2. To opt in to
protocol-independent response shapes, set legacy_responses=False.
For new projects, we recommend opting out of legacy response compatibility by
setting legacy_responses=False. This makes redis-py return unified Python
response shapes for affected commands whether the connection uses RESP2 or
RESP3. Existing applications can keep the default legacy-compatible behavior
while they migrate response handling at their own pace.
>>> import redis
>>> r = redis.Redis(host='localhost', port=6379, db=0, legacy_responses=False)
See the unified responses migration guide
for activation instructions and command-by-command response differences. For
RESP3-specific behavior, see the RESP3 features guide.
Connection Pools
By default, redis-py uses a connection pool to manage connections. Each instance of a Redis class receives its own connection pool. You can however define your own redis.ConnectionPool.
>>> pool = redis.ConnectionPool(host='localhost', port=6379, db=0)
>>> r = redis.Redis(connection_pool=pool)
Alternatively, you might want to look at Async connections, or Cluster connections, or even Async Cluster connections.
Redis Commands
There is built-in support for all of the out-of-the-box Redis commands. They are exposed using the raw Redis command names (HSET, HGETALL, etc.) except where a word (i.e. del) is reserved by the language. The complete set of commands can be found here, or the documentation.
Advanced Topics
The official Redis command documentation
does a great job of explaining each command in detail. redis-py attempts
to adhere to the official command syntax. There are a few exceptions:
MULTI/EXEC: These are implemented as part of the Pipeline class.
The pipeline is wrapped with the MULTI and EXEC statements by
default when it is executed, which can be disabled by specifying
transaction=False. See more about Pipelines below.
SUBSCRIBE/LISTEN: Similar to pipelines, PubSub is implemented as
a separate class as it places the underlying connection in a state
where it can't execute non-pubsub commands. Calling the pubsub
method from the Redis client will return a PubSub instance where you
can subscribe to channels and listen for messages. You can only call
PUBLISH from the Redis client (see this comment on issue
#151
for details).
For more details, please see the documentation on advanced topics page.
Pipelines
The following is a basic example of a Redis pipeline, a method to optimize round-trip calls, by batching Redis commands, and receiving their results as a list.
>>> pipe = r.pipeline()
>>> pipe.set('foo', 5)
>>> pipe.set('bar', 18.5)
>>> pipe.set('blee', "hello world!")
>>> pipe.execute()
[True, True, True]
PubSub
The following example shows how to utilize Redis Pub/Sub to subscribe to specific channels.
>>> r = redis.Redis(...)
>>> p = r.pubsub()
>>> p.subscribe('my-first-channel', 'my-second-channel', ...)
>>> p.get_message()
{'pattern': None, 'type': 'subscribe', 'channel': b'my-second-channel', 'data': 1}
Redis’ search and query capabilities default dialect
Release 6.0.0 introduces a client-side default dialect for Redis’ search and query capabilities.
By default, the client now overrides the server-side dialect with version 2, automatically appending DIALECT 2 to commands like FT.AGGREGATE and FT.SEARCH.
Important: Be aware that the query dialect may impact the results returned. If needed, you can revert to a different dialect version by configuring the client accordingly.
>>> from redis.commands.search.field import TextField
>>> from redis.commands.search.query import Query
>>> from redis.commands.search.index_definition import IndexDefinition
>>> import redis
>>> r = redis.Redis(host='localhost', port=6379, db=0)
>>> r.ft().create_index(
>>> (TextField("name"), TextField("lastname")),
>>> definition=IndexDefinition(prefix=["test:"]),
>>> )
>>> r.hset("test:1", "name", "James")
>>> r.hset("test:1", "lastname", "Brown")
>>> # Query with default DIALECT 2
>>> query = "@name: James Brown"
>>> q = Query(query)
>>> res = r.ft().search(q)
>>> # Query with explicit DIALECT 1
>>> query = "@name: James Brown"
>>> q = Query(query).dialect(1)
>>> res = r.ft().search(q)
You can find further details in the query dialect documentation.
Multi-database client (Active-Active)
The multi-database client allows your application to connect to multiple Redis databases, which are typically replicas of each other. It is designed to work with Redis Software and Redis Cloud Active-Active setups. The client continuously monitors database health, detects failures, and automatically fails over to the next healthy database using a configurable strategy. When the original database becomes healthy again, the client can automatically switch back to it.
This is useful when:
- You have more than one Redis deployment. This might include two independent Redis servers or two or more Redis databases replicated across multiple active-active Redis Enterprise clusters.
- You want your application to connect to one deployment at a time and to fail over to the next available deployment if the first deployment becomes unavailable.
For the complete failover configuration options and examples, see the Multi-database client docs.
Bulk hash ingestion (HIMPORT)
Redis 8.10 adds the HIMPORT command family for loading many hashes that share
the same set of field names: register the field names once with himport_prepare,
then create each hash by sending only its values. Keys written this way are regular
hashes — every hash command works on them.
r.himport_prepare("users", ["name", "email", "age"])
r.himport_set("user:1", "users", ["alice", "[email protected]", "25"])
r.himport_set("user:2", "users", ["bob", "[email protected]", "30"])
r.himport_discard("users") # => 1
Values pair positionally with the prepared fields. Hash enumeration order
(HGETALL, HKEYS) is not guaranteed to match the prepare order.
Fieldsets are connection state. A prepared fieldset lives in the server-side
session of the physical connection that prepared it: it is invisible to other
connections and destroyed by a disconnect or RESET. redis-py handles this for you —
himport_prepare records the fieldset in a client-level registry, and the PREPARE
is applied lazily on whatever pooled connection serves each himport_set (and
re-applied automatically after a reconnect, RESET, or Sentinel/cluster failover).
You declare each fieldset once per client with himport_prepare; there is no
constructor argument for it.
For the highest ingestion throughput, send the PREPARE and its SETs in one
pipeline — a single batch always executes on one connection:
with r.pipeline(transaction=False) as pipe:
pipe.himport_prepare("users", ["name", "email", "age"])
for uid, row in rows:
pipe.himport_set(f"user:{uid}", "users", row)
pipe.execute()
The automatic re-prepare applies to direct calls only, not to commands inside
pipeline/transaction blocks: a batched himport_set relies on the single
pre-flight PREPARE in that batch.
With RedisCluster, himport_prepare / himport_discard / himport_discard_all
update the client's shared, cluster-wide registry and return immediately — like the
standalone API, they perform no server I/O of their own. The server-side PREPARE
(and, after a discard, DISCARD) is applied lazily on each node's connection the
next time it serves an himport_set, and re-applied after reconnects or failover;
himport_set itself routes by the key's hash slot. A discard is therefore not
removed from every server session at once: each connection drops the fieldset on its
next himport_set (or on disconnect). With Sentinel, call
himport_prepare on the long-lived client returned by master_for(...); the fieldset
survives failover automatically. HIMPORT is not supported on the multi-database
(Active-Active) client.
The async client mirrors this exactly:
await r.himport_prepare("users", ["name", "email", "age"])
await r.himport_set("user:1", "users", ["alice", "[email protected]", "25"])
Author
redis-py is developed and maintained by Redis Inc. It can be found here, or downloaded from pypi.
Special thanks to:
- Andy McCurdy ([email protected]) the original author of redis-py.
- Ludovico Magnocavallo, author of the original Python Redis client,
from which some of the socket code is still used.
- Alexander Solovyov for ideas on the generic response callback
system.
- Paul Hubbard for initial packaging support.
redis-py 是 Redis 键值数据库的官方 Python 客户端，也就是你的 Python 代码用来和 Redis 服务器通信的接口。